TimeMesh: an educational historical game

The TIMEMESH game, developed in the scope of the European Project SELEAG, is an educational game for learning history, culture and social relations. It is supported by an extensible, online, multi-language, multi-player, collaborative and social platform for sharing and acquiring knowledge of the history of European regions. The game has been already used, with remarkable success, in different European countries like Portugal, Spain, England, Slovenia, Estonia and Belgium.

Methodology for in-game certification in serious games

Serious games are starting to attain a higher role as tools for learning in various contexts, but in particular in areas such as education and training. Due to its characteristics, such as rules, behavior simulation and feedback to the player's actions, serious games provide a favorable learning environment where errors can occur without real life penalty and students get instant feedback from challenges. These challenges are in accordance with the intended objectives and will self-adapt and repeat according to the student’s difficulty level. Through motivating and engaging environments, which serve as base for problem solving and simulation of different situations and contexts, serious games have a great potential to aid players developing professional skills. But, how do we certify the acquired knowledge and skills? With this work we intend to propose a methodology to establish a relationship between the game mechanics of serious games and an array of competences for certification, evaluating the applicability of various aspects in the design and development of games such as the user interfaces and the gameplay, obtaining learning outcomes within the game itself. Through the definition of game mechanics combined with the necessary pedagogical elements, the game will ensure the certification. This paper will present a matrix of generic skills, based on the European Framework of Qualifications, and the definition of the game mechanics necessary for certification on tour guide training context. The certification matrix has as reference axes: skills, knowledge and competencies, which describe what the students should learn, understand and be able to do after they complete the learning process. The guides-interpreters welcome and accompany tourists on trips and visits to places of tourist interest and cultural heritage such as museums, palaces and national monuments, where they provide various information. Tour guide certification requirements include skills and specific knowledge about foreign languages and in the areas of History, Ethnology, Politics, Religion, Geography and Art of the territory where it is inserted. These skills are communication, interpersonal relationships, motivation, organization and management. This certification process aims to validate the skills to plan and conduct guided tours on the territory, demonstrate knowledge appropriate to the context and finally match a good group leader. After defining which competences are to be certified, the next step is to delineate the expected learning outcomes, as well as identify the game mechanics associated with it. The game mechanics, as methods invoked by agents for interaction with the game world, in combination with game elements/objects allows multiple paths through which to explore the game environment and its educational process. Mechanics as achievements, appointments, progression, reward schedules or status, describe how game can be designed to affect players in unprecedented ways. In order for the game to be able to certify tour guides, the design of the training game will incorporate a set of theoretical and practical tasks to acquire skills and knowledge of various transversal themes. For this end, patterns of skills and abilities in acquiring different knowledge will be identified.

TimeMesh – a serious game for european citizenship

Serious games are games where the entertainment aspect is not the most relevant motivation or objective. TimeMesh is an online, multi-language, multiplayer, collaborative and social game platform for sharing and acquiring knowledge of the history of European regions. As such it is a serious game with educational characteristics. This article evaluates the use of TimeMesh with students of 13 and 14 years-old. It shows that this game is already a significant learning tool about European citizenship.

Mismatch negativity in childhood temporal lobe epilepsy: a proposed paradigm for testing central auditory processing

Background: Temporal lobe epilepsy (TLE) is a neurological disorder that directly affects cortical areas responsible for auditory processing. The resulting abnormalities can be assessed using event-related potentials (ERP), which have high temporal resolution. However, little is known about TLE in terms of dysfunction of early sensory memory encoding or possible correlations between EEGs, linguistic deficits, and seizures. Mismatch negativity (MMN) is an ERP component – elicited by introducing a deviant stimulus while the subject is attending to a repetitive behavioural task – which reflects pre-attentive sensory memory function and reflects neuronal auditory discrimination and perceptional accuracy. Hypothesis: We propose an MMN protocol for future clinical application and research based on the hypothesis that children with TLE may have abnormal MMN for speech and non-speech stimuli. The MMN can be elicited with a passive auditory oddball paradigm, and the abnormalities might be associated with the location and frequency of epileptic seizures. Significance: The suggested protocol might contribute to a better understanding of the neuropsychophysiological basis of MMN. We suggest that in TLE central sound representation may be decreased for speech and non-speech stimuli. Discussion: MMN arises from a difference to speech and non-speech stimuli across electrode sites. TLE in childhood might be a good model for studying topographic and functional auditory processing and its neurodevelopment, pointing to MMN as a possible clinical tool for prognosis, evaluation, follow-up, and rehabilitation for TLE.

Distributed computer-controlled systems: the DEAR-COTS approach

This paper proposes a new architecture targeting real-time and reliable Distributed Computer-Controlled Systems (DCCS). This architecture provides a structured approach for the integration of soft and/or hard real-time applications with Commercial O -The-Shelf (COTS) components. The Timely Computing Base model is used as the reference model to deal with the heterogeneity of system components with respect to guaranteeing the timeliness of applications. The reliability and availability requirements of hard real-time applications are guaranteed by a software-based fault-tolerance approach.

Supporting real-time distributed computer-controlled systems with multi-hop P-NET networks

Fieldbus communication networks aim to interconnect sensors, actuators and controllers within process control applications. Therefore, they constitute the foundation upon which real-time distributed computer-controlled systems can be implemented. P-NET is a fieldbus communication standard, which uses a virtual token-passing medium-access-control mechanism. In this paper pre-run-time schedulability conditions for supporting real-time traffic with P-NET networks are established. Essentially, formulae to evaluate the upper bound of the end-to-end communication delay in P-NET messages are provided. Using this upper bound, a feasibility test is then provided to check the timing requirements for accessing remote process variables. This paper also shows how P-NET network segmentation can significantly reduce the end-to-end communication delays for messages with stringent timing requirements.

An architecture for reliable distributed computer-controlled systems

In Distributed Computer-Controlled Systems (DCCS), both real-time and reliability requirements are of major concern. Architectures for DCCS must be designed considering the integration of processing nodes and the underlying communication infrastructure. Such integration must be provided by appropriate software support services. In this paper, an architecture for DCCS is presented, its structure is outlined, and the services provided by the support software are presented. These are considered in order to guarantee the real-time and reliability requirements placed by current and future systems.

A communication support for real-time distributed computer controlled systems

In this paper, we analyse the ability of P-NET [1] fieldbus to cope with the timing requirements of a Distributed Computer Control System (DCCS), where messages associated to discrete events should be made available within a maximum bound time. The main objective of this work is to analyse how the network access and queueing delays, imposed by P-NET’s virtual token Medium Access Control (MAC) mechanism, affect the realtime behaviour of the supported DCCS.

Projecto de avaliação de interfaces – PAI

Para obtenção do grau de Doutor pela Universidade de Vigo com menção internacional Departamento de Informática

Using a prioritized MAC protocol to execute the database operation join in networked embedded computer systems

Database query languages on relations (for example SQL) make it possible to join two relations. This operation is very common in desktop/server database systems but unfortunately query processing systems in networked embedded computer systems currently do not support this operation; specifically, the query processing systems TAG, TinyDB, Cougar do not support this. We show how a prioritized medium access control (MAC) protocol can be used to efficiently execute the database operation join for networked embedded computer systems where all computer nodes are in a single broadcast domain.

H-NAMe: specifying, implementing and testing a hidden-node avoidance mechanism for wireless sensor networks

The hidden-node problem has been shown to be a major source of Quality-of-Service (QoS) degradation in Wireless Sensor Networks (WSNs) due to factors such as the limited communication range of sensor nodes, link asymmetry and the characteristics of the physical environment. In wireless contention-based Medium Access Control protocols, if two nodes that are not visible to each other transmit to a third node that is visible to the formers, there will be a collision – usually called hidden-node or blind collision. This problem greatly affects network throughput, energy-efficiency and message transfer delays, which might be particularly dramatic in large-scale WSNs. This technical report tackles the hidden-node problem in WSNs and proposes HNAMe, a simple yet efficient distributed mechanism to overcome it. H-NAMe relies on a grouping strategy that splits each cluster of a WSN into disjoint groups of non-hidden nodes and then scales to multiple clusters via a cluster grouping strategy that guarantees no transmission interference between overlapping clusters. We also show that the H-NAMe mechanism can be easily applied to the IEEE 802.15.4/ZigBee protocols with only minor add-ons and ensuring backward compatibility with the standard specifications. We demonstrate the feasibility of H-NAMe via an experimental test-bed, showing that it increases network throughput and transmission success probability up to twice the values obtained without H-NAMe. We believe that the results in this technical report will be quite useful in efficiently enabling IEEE 802.15.4/ZigBee as a WSN protocol.

i-GAME: an implicit GTS allocation mechanism in IEEE 802.15.4 for time-sensitive wireless sensor networks

The IEEE 802.15.4 Medium Access Control (MAC) protocol is an enabling technology for time sensitive wireless sensor networks thanks to its Guaranteed-Time Slot (GTS) mechanism in the beacon-enabled mode. However, the protocol only supports explicit GTS allocation, i.e. a node allocates a number of time slots in each superframe for exclusive use. The limitation of this explicit GTS allocation is that GTS resources may quickly disappear, since a maximum of seven GTSs can be allocated in each superframe, preventing other nodes to benefit from guaranteed service. Moreover, the GTSs may be only partially used, resulting in wasted bandwidth. To overcome these limitations, this paper proposes i-GAME, an implicit GTS Allocation Mechanism in beacon-enabled IEEE 802.15.4 networks. The allocation is based on implicit GTS allocation requests, taking into account the traffic specifications and the delay requirements of the flows. The i-GAME approach enables the use of a GTS by multiple nodes, while all their (delay, bandwidth) requirements are still satisfied. For that purpose, we propose an admission control algorithm that enables to decide whether to accept a new GTS allocation request or not, based not only on the remaining time slots, but also on the traffic specifications of the flows, their delay requirements and the available bandwidth resources. We show that our proposal improves the bandwidth utilization compared to the explicit allocation used in the IEEE 802.15.4 protocol standard. We also present some practical considerations for the implementation of i-GAME, ensuring backward compatibility with the IEEE 801.5.4 standard with only minor add-ons.

Implementation of the i-GAME mechanism in IEEE 802.15.4 WPANs

This technical report describes the implementation details of the Implicit GTS Allocation Mechanism (i-GAME), for the IEEE 802.15.4 protocol. The i-GAME was implemented in nesC/TinyOS for the CrossBow MICAz mote, over our own implementation of the IEEE 802.15.4 protocol stack. This document provides the implementation details, including a description of the i-GAME software interfaces.

Effect of plug-filling, Testing velocity and temperature on the tensile strength of strap repairs on aluminium structures

In this work, an experimental study was performed on the influence of plug-filling, loading rate and temperature on the tensile strength of single-strap (SS) and double-strap (DS) repairs on aluminium structures. Whilst the main purpose of this work was to evaluate the feasibility of plug-filling for the strength improvement of these repairs, a parallel study was carried out to assess the sensitivity of the adhesive to external features that can affect the repairs performance, such as the rate of loading and environmental temperature. The experimental programme included repairs with different values of overlap length (L O = 10, 20 and 30 mm), and with and without plug-filling, whose results were interpreted in light of experimental evidence of the fracture modes and typical stress distributions for bonded repairs. The influence of the testing speed on the repairs strength was also addressed (considering 0.5, 5 and 25 mm/min). Accounting for the temperature effects, tests were carried out at room temperature (≈23°C), 50 and 80°C. This permitted a comparative evaluation of the adhesive tested below and above the glass transition temperature (T g), established by the manufacturer as 67°C. The combined influence of these two parameters on the repairs strength was also analysed. According to the results obtained from this work, design guidelines for repairing aluminium structures were

Real time fault injection using a modified debugging infrastructure

Dependability is a critical factor in computer systems, requiring high quality validation & verification procedures in the development stage. At the same time, digital devices are getting smaller and access to their internal signals and registers is increasingly complex, requiring innovative debugging methodologies. To address this issue, most recent microprocessors include an on-chip debug (OCD) infrastructure to facilitate common debugging operations. This paper proposes an enhanced OCD infrastructure with the objective of supporting the verification of fault-tolerant mechanisms through fault injection campaigns. This upgraded on-chip debug and fault injection (OCD-FI) infrastructure provides an efficient fault injection mechanism with improved capabilities and dynamic behavior. Preliminary results show that this solution provides flexibility in terms of fault triggering and allows high speed real-time fault injection in memory elements